07-24-2010, 08:50 AM
The shipper will request the car and at that time will state their particular requirements as to car icing. Not all shipments moving in reefers require cooling, either. In a series on PFE reefers in RMC, it was noted that in 1947, 20% of all shipments were of canned goods. Many ice reefers featured "stage icing", which consisted mainly of drop-down grates within the ice bunkers, allowing a partial charge of ice. Many cars also had "convertible bunkers", which could be folded against the interior ends of the car, allowing a greater cubic capacity for lading that required no cooling.
I cold weather, charcoal heaters were often placed in the ice bunkers (without the ice, of course
) to keep the lading from freezing.
Some cargo (meat and fish) required temperatures colder than could be obtained with ice alone, so salt would be mixed with the ice to lower its freezing point - the shipper usually specified the ratio.
Some lading, such as fresh fish, might be "top iced", with crushed ice applied directly atop it - this was usually done at point of loading.
For fairly short trips of some perishable commodities, such as fruit and vegetables, the reefer could be operated as a ventilator car, with the bunker hatches propped open but no ice in the bunkers.
Wayne
I cold weather, charcoal heaters were often placed in the ice bunkers (without the ice, of course
) to keep the lading from freezing.Some cargo (meat and fish) required temperatures colder than could be obtained with ice alone, so salt would be mixed with the ice to lower its freezing point - the shipper usually specified the ratio.
Some lading, such as fresh fish, might be "top iced", with crushed ice applied directly atop it - this was usually done at point of loading.
For fairly short trips of some perishable commodities, such as fruit and vegetables, the reefer could be operated as a ventilator car, with the bunker hatches propped open but no ice in the bunkers.
Wayne